C is a structured, procedural programming language that has been widely used both for operating systems and applications and that has had a wide following in the academic community. Many versions of UNIX-based operating systems are written in C. C is being rapidly replaced as "the" programming language by C++, a superset of the C language that uses an entirely different set of programming concepts, and by Java, a language similar to but simpler than C++, that was designed for use in distributed networks.